package com.lx.servlet;

import javax.imageio.ImageIO;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.IOException;
import java.util.Random;

@WebServlet("/checkCodeServlet")
public class CheckCodeServlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doGet(request,response);
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        int width = 100,height=50;
        //创建一对象，在内存中图片（验证码）
        BufferedImage image = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);

        //2. 美化图片
        //2.1 填充背景色
        Graphics g = image.getGraphics();  //画笔对象
        g.setColor(Color.PINK);           //设置画笔颜色
        g.fillRect(0,0,width,height);

        //2.2 画边框
        g.setColor(Color.BLUE);
        g.drawRect(0,0,width,height);

        String str = "zxcvbnmlkjhgfdsaqwertyuiop1234567890";
        //生成随机角标
        Random random = new Random();

        for (int i = 1; i <=4 ; i++) {
            int index = random.nextInt(str.length());
            //获取字符
            char ch = str.charAt(index);
            //2.3 写验证码
            g.drawString(ch+"",width/5*i,height/2);
        }
        //2.4 画干扰线
        g.setColor(Color.green);
        //随机生成坐标点
        for (int i = 1; i <=5 ; i++) {
            int x1 = random.nextInt(width);
            int x2 = random.nextInt(width);
            int y1 = random.nextInt(height);
            int y2 = random.nextInt(height);
            g.drawLine(x1,x2,y1,y2);

        }

        //3 将图片输出到页面显示
        ImageIO.write(image,"jpg",response.getOutputStream());
    }
}
